Erasable markerboards and other erasable marker surfaces are well known. Typically, these markerboards and surfaces have been made of durable polymeric materials or plastics that can withstand being printed upon usually with erasable liquid inks and then reused after removal of the ink images. The marker surface must be impermeable or nonreactive so as not to permanently receive the ink image. Otherwise, the markerboard surface would not be erasable and reusable, thus defeating its purpose.
In many instances, it is desirable to print permanent information or indicia on the markerboard surface such as charted lines, numbers, words or other markings. The objective of such permanent information is to provide a format or background on which the erasable ink images are to be placed. Then, after the erasable ink images are printed on the surface and erased, the permanent information remains on the surface for reuse as the format or background. For instance, calendars, monthly planners, bulletin boards, personnel status boards, and many other information boards desirably have permanent information on them to serve as background for the erasable ink images.
Difficulties have been encountered in making durable marker surfaces with permanent background indicia. Heretofore for many years, printing or silk screen techniques have been employed to place somewhat permanent background indicia on the marker surface. It has been found, however, that such indicia do not wear well and, as the board is continuously used and erased, the indicia will fade, be rubbed off or distorted. Furthermore, bonding and clarity of permanent indicia on the marking surface has not been satisfactorily achieved. For many years, silk screen techniques have been employed to impart a pattern indicia upon markerboard surfaces. The desirable feature of a durable or nonreactive surface for temporarily receiving the ink image on the silk-screened markerboard usually diminishes the life of the permanent background indicia. It has become exceedingly difficult to obtain a durable silk-screened or other image of a permanent nature on a markerboard that has the desirable characteristics of erasability of ink images.
There is a need for a markerboard having a surface for receiving erasable ink images and a permanent background or indicia that can withstand continuous use and erasing means so that the ink images may be removed and the board reused.